Apparatus and methods for achieving lock-out of a downhole tool

Abstract

Apparatus and associated methods provide convenient and reliable deposition of a radially deflectable blocking member relative to a downhole tool. In a described embodiment of the apparatus, a lock-out tool has mechanisms which effect latching of the tool to an internal profile of a safety valve, displacement of an opening prong of the safety valve to open the safety valve, and deposition of an expandable ring to prevent closure of the safety valve. The ring is accurately positioned by the tool and is constructed in a manner which enables it to resist relatively large axial loads, but which also enable it to be significantly radially compressed.

What is claimed is: 
     
       1. A radially deflectable ring operatively positionable relative to first and second members of a downhole tool to limit displacement of the first member relative to the second member, the ring comprising: a series of generally circumferentially spaced apart and generally axially extending cantilevers, the cantilevers being insertable axially between a portion of the first member and a portion of the second member, each of the cantilevers having first and second opposite ends, each of the first opposite ends being attached to another of the first opposite ends, and each of the second opposite ends being attached to another of the second opposite ends.   
     
     
       2. The ring according to claim 1, further comprising first and second series of generally circumferentially spaced apart segments, the first segments being axially spaced apart from the second segments, and wherein each of the cantilever first opposite ends is attached to a corresponding one of the first segments, and each of the cantilever second opposite ends is attached to a corresponding one of the second segments. 
     
     
       3. The ring according to claim 2, wherein at least one of the first and second series of segments is generally annular-shaped. 
     
     
       4. The ring according to claim 1, wherein each of the cantilevers is attached to two other ones of the cantilevers, the series of cantilevers thereby forming the ring in a generally circumferentially continuous manner. 
     
     
       5. The ring according to claim 1, wherein the first opposite ends are attached to each other via a first series of generally circumferentially spaced apart segments. 
     
     
       6. The ring according to claim 5, wherein the second opposite ends are attached to each other via a second series of generally circumferentially spaced apart segments. 
     
     
       7. A method of locking-out a safety valve operatively positioned within a subterranean wellbore, the method comprising the steps of: locking a tool within the safety valve in a fixed position relative to an outer housing of the safety valve; and   operating the tool to deposit a radially expandable ring within the safety valve and thereby restrict displacement of an actuator member of the safety valve.   
     
     
       8. The method according to claim 7, wherein the step of locking further comprises latching the tool to an internal profile attached to the outer housing. 
     
     
       9. The method according to claim 8, wherein the step of locking further comprises radially outwardly extending a latch member into engagement with the internal profile. 
     
     
       10. The method according to claim 9, wherein the step of locking further comprises releasably securing the latch member in its engagement with the internal profile. 
     
     
       11. The method according to claim 7, wherein the step of operating the tool further comprises displacing the actuator member from a position in which the safety valve is closed to a position in which the safety valve is open. 
     
     
       12. The method according to claim 11, wherein the displacing step is performed by engaging a portion of the tool with the actuator member, and displacing the tool portion relative to the outer housing. 
     
     
       13. The method according to claim 11, wherein the displacing step is performed by applying fluid pressure to the tool, and wherein the tool is free of sealing engagement with the actuator member. 
     
     
       14. The method according to claim 7, wherein in the operating step, the ring is deposited in an annular recess axially between a portion of the actuator member and an internal shoulder of the safety valve. 
     
     
       15. The method according to claim 7, wherein the operating step is performed by applying a sequence of increasing fluid pressure to the tool. 
     
     
       16. The method according to claim 15, wherein a first portion of the sequence causes the tool to engage the actuator member. 
     
     
       17. The method according to claim 16, wherein a second portion of the sequence causes the tool to displace the actuator member. 
     
     
       18. For use in locking-out a safety valve having an actuator member operatively displaceable relative to an internal profile attached to an outer housing of the safety valve, apparatus comprising: a latch mechanism capable of engaging the internal profile and securing the latch mechanism in a fixed position relative to the outer housing;   a displacement mechanism attached to the latch mechanism, the displacement mechanism being capable of engaging the actuator member and displacing the actuator member relative to the latch mechanism to a first position in which the safety valve is open; and   a blocking member carried relative to the displacement mechanism, the blocking member being deposited nondestructively within the safety valve and restricting displacement of the actuator member when the actuator member is displaced to the first position by the displacement mechanism.   
     
     
       19. The apparatus according to claim 18, wherein the safety valve further has a seal bore, the actuator member being axially slidably disposed between the internal profile and the seal bore, and wherein the displacement mechanism includes a seal capable of sealingly engaging the seal bore when the latch mechanism engages the internal profile. 
     
     
       20. The apparatus according to claim 19, wherein the seal is attached to the latch mechanism, such that the seal is secured in its position relative to the outer housing when the actuator member is displaced by the displacement mechanism. 
     
     
       21. The apparatus according to claim 18, wherein the displacement mechanism includes at least one radially outwardly extendable engagement member capable of engaging the actuator member. 
     
     
       22. The apparatus according to claim 21, wherein the displacement mechanism is configured to displace the engagement member relative to the latch mechanism in order to displace the actuator member to the first position. 
     
     
       23. The apparatus according to claim 22, wherein the displacement mechanism further includes a piston attached to the engagement member, the piston being capable of displacing relative to the latch mechanism in response to fluid pressure applied to the piston. 
     
     
       24. The apparatus according to claim 23, further comprising a pressure relief device, the pressure relief device being configured to relieve the fluid pressure applied to the piston after the blocking member is deposited within the safety valve. 
     
     
       25. The apparatus according to claim 18, wherein the blocking member is a generally circumferentially continuous ring. 
     
     
       26. The apparatus according to claim 25, wherein the ring includes a series of interconnected generally axially extending cantilevers. 
     
     
       27. The apparatus according to claim 18, wherein the blocking member is radially inwardly retained by a first retainer secured to the displacement mechanism and by a second retainer axially slidingly disposed relative to the displacement mechanism. 
     
     
       28. The apparatus according to claim 27, wherein the second retainer is releasably secured to the displacement mechanism, the second retainer being released for sliding displacement relative to the displacement mechanism when the displacement mechanism is displaced a predetermined distance relative to the latch mechanism. 
     
     
       29. Apparatus for locking-out a safety valve operatively positioned within a subterranean wellbore, the apparatus comprising: a radially deflectable ring including a series of generally circumferentially spaced apart and generally axially extending cantilevers, each of the cantilevers having first and second opposite ends, each of the first opposite ends being attached to another of the first opposite ends, and each of the second opposite ends being attached to another of the second opposite ends.   
     
     
       30. The apparatus according to claim 29, further comprising first and second series of generally circumferentially spaced apart segments, the first segments being axially spaced apart from the second segments, and wherein each of the cantilever first opposite ends is attached to a corresponding one of the first segments, and each of the cantilever second opposite ends is attached to a corresponding one of the second segments. 
     
     
       31. The apparatus according to claim 30, wherein at least one of the first and second series of segments is generally annular-shaped. 
     
     
       32. The apparatus according to claim 29, wherein each of the cantilevers is attached to two other ones of the cantilevers, the series of cantilevers thereby forming the ring in a generally circumferentially continuous manner. 
     
     
       33. The apparatus according to claim 29, wherein the first opposite ends are attached to each other via a first series of generally circumferentially spaced apart segments. 
     
     
       34. The apparatus according to claim 33, wherein the second opposite ends are attached to each other via a second series of generally circumferentially spaced apart segments. 
     
     
       35. A method of locking-out a safety valve operatively positioned within a subterranean wellbore, the method comprising the steps of: sealingly engaging a lock-out tool with a seal bore of the safety valve, the seal bore being attached to an outer housing of the safety valve;   securing the lock-out tool axially within the safety valve relative to the outer housing;   applying fluid pressure to the lock-out tool to thereby cause a portion of the lock-out tool to engage an actuator member of the safety valve and displace the actuator member relative to the outer housing; and   to axially elongate an annular recess within the safety valve; and   depositing a blocking member within the annular recess to thereby restrict displacement of the actuator member relative to the outer housing, the blocking member being a ring having a generally circumferentially continuous construction, the ring having a series of interconnected generally axially extending cantilevers, the cantilevers being laterally deflectable to thereby permit radial compression of the ring.   
     
     
       36. The method according to claim 35, wherein the fluid pressure applying step further comprises opening the safety valve by such displacement of the actuator member. 
     
     
       37. The method according to claim 35, wherein in the securing step, the lock-out tool is secured to an internal profile of the safety valve, the actuator member being disposed axially between the seal bore and the internal profile. 
     
     
       38. A method of limiting displacement of a first member of a tool operatively positioned within a subterranean wellbore, the method comprising the steps of: locking an apparatus within the tool in a fixed position relative to a second member of the tool; and   operating the apparatus to deposit a circumferentially continuous, radially expandable blocking member relative to the tool and thereby restrict displacement of the first member.   
     
     
       39. The method according to claim 38, wherein the step of locking further comprises latching the apparatus to an internal profile formed on the second member. 
     
     
       40. The method according to claim 39, wherein the step of locking further comprises radially outwardly extending a latch member into engagement with the internal profile. 
     
     
       41. The method according to claim 40, wherein in the step of locking further comprises releasably securing the latch member in its emgagement with the internal profile. 
     
     
       42. The method according to claim 38, wherein the step of operating the apparatus further comprises displacing the first member from a first position to a second position to thereby operate the tool. 
     
     
       43. The method according to claim 42, wherein the displacing step is performed by engaging a portion of the apparatus with the first member, and displacing the apparatus portion relative to the second member. 
     
     
       44. The method according to claim 42, wherein the displacing step is performed by applying fluid pressure to the apparatus, and wherein the apparatus is free of sealing engagement with the first member. 
     
     
       45. The method according to claim 38, wherein in the operating step, the blocking member is deposited in an annular recess within the tool. 
     
     
       46. The method according to claim 38, wherein the operating step is performed by applying a sequence of increasing fluid pressure to the apparatus. 
     
     
       47. The method according to claim 46, wherein a first portion of the sequence causes the apparatus to engage the first member. 
     
     
       48. The method according to claim 47, wherein a second portion of the sequence causes the apparatus to displace the first member. 
     
     
       49. Apparatus for limiting movement of a member of a tool operatively positioned within a subterranean wellbore, the apparatus comprising: a radially deflectable ring including a series of generally circumferentially spaced apart and generally axially extending cantilevers, the ring being releasably retained relative to the remainder of the apparatus,   whereby the apparatus is capable of depositing the ring relative to the tool.   
     
     
       50. The apparatus according to claim 49, wherein the ring further includes first and second series of generally circumferentially spaced apart segments, the first segments being axially spaced apart from the second segments, and wherein each of the cantilevers has opposite ends, one of each of the cantilever opposite ends being attached to a corresponding one of the first segments, and the other of each of the cantilever opposite ends being attached to a corresponding one of the second segments. 
     
     
       51. The method according to claim 50, wherein each of the first segments is attached to two of the one of the cantilever opposite ends, and wherein each of the second segments is attached to two of the other of the cantilever oppposite ends. 
     
     
       52. The apparatus according to claim 50, wherein at least one of the first and second series of segments is generally annular-shaped. 
     
     
       53. The apparatus according to claim 49, wherein each of the cantilevers is attached to two other ones of the cantilevers, the series of cantilevers thereby forming the ring in a generally circumferentially continuous manner. 
     
     
       54. A The apparatus according to claim 49, wherein each of the cantilevers has first and second opposite ends, each of the first opposite ends being attached to another of the first opposite ends, and each of the second opposite ends being attached to another of the second opposite ends. 
     
     
       55. The apparatus according to claim 54, wherein the first opposite ends are attached to each other via a first series of generally circumferentially spaced apart segments. 
     
     
       56. The apparatus according to claim 55, wherein the second opposite ends are attached to each other via a second series of generally circumferentially spaced apart segments. 
     
     
       57. For use in limiting displacement of a first member operatively displaceable relative to a second member of a tool, apparatus comprising: a latch mechanism capable of engaging a profile secured relative to the second member, and thereby securing the latch mechanism in a fixed position relative to the second member;   a displacement mechanism attached to the latch mechanism, the displacement mechanism being capable of engaging the first member and displacing the first member relative to the latch mechanism; and   an expandable blocking member carried relative to the displacement mechanism, the expandable blocking member being deposited relative to the tool and limiting displacement of the first member when the first member is displaced by the displacement mechanism.   
     
     
       58. The apparatus according to claim 57, wherein the tool further has a seal bore, the first member being axially slidably disposed between the profile and the seal bore, and wherein the displacement mechanism includes a seal capable of sealingly engaging the seal bore when the latch mechanism engages the profile. 
     
     
       59. The apparatus according to claim 58, wherein the seal is attached to the latch mechanism, such that the seal is secured in its position relative to the second member when the first member is displaced by the displacement mechanism. 
     
     
       60. The apparatus according to claim 57, wherein the displacement mechanism includes at least one radially displaceable engagement member capable of engaging the first member. 
     
     
       61. The apparatus according to claim 60, wherein the displacement mechanism is configured to displace the engagement member relative to the latch mechanism in order to displace the first member relative to the second member. 
     
     
       62. The apparatus according to claim 61, wherein the displacement mechanism further includes a piston attached to the engagement member, the piston being capable of displacing relative to the latch mechanism in response to fluid pressure applied to the piston. 
     
     
       63. The apparatus according to claim 62, further comprising a pressure relief device, the pressure relief device being configured to relieve the fluid pressure applied to the piston after the blocking member is deposited relative to the tool. 
     
     
       64. The apparatus according to claim 57, wherein the blocking member is a generally circumferentially continuous ring. 
     
     
       65. The apparatus according to claim 64, wherein the ring includes a series of interconnected generally axially extending cantilevers. 
     
     
       66. The apparatus according to claim 57, wherein the blocking member is radially inwardly retained by a first retainer secured to the displacement mechanism and by a second retainer axially slidingly disposed relative to the displacement mechanism. 
     
     
       67. The apparatus according to claim 66, wherein the second retainer is releasably secured to the displacement mechanism, the second retainer being released for sliding displacement relative to the displacement mechanism when the displacement mechanism is displaced a predetermined distance relative to the latch mechanism. 
     
     
       68. The apparatus according to claim 59, wherein the the displacement mechanism is configured to displace the first member in a first direction relative to the latch mechanism, and further comprising a biasing member, the biasing member biasing the displacement mechanism in a second direction relative to the latch mechanism, the second direction being oppposite to the first direction. 
     
     
       69. The apparatus according to claim 68, wherein the biasing member biases the displacement mechanism toward a position in which the displacement member disengages the first member.